A5021018765- Topological Materials and Phenomena
- Graphene research and applications
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Quantum and electron transport phenomena
- Analytical Chemistry and Sensors
- Conducting polymers and applications
- 2D Materials and Applications
- Semiconductor Quantum Structures and Devices
- Advanced Semiconductor Detectors and Materials
- Electronic and Structural Properties of Oxides
- Advanced Condensed Matter Physics
- Rare-earth and actinide compounds
- Semiconductor materials and interfaces
- Chalcogenide Semiconductor Thin Films
- Phase-change materials and chalcogenides
- Advanced Sensor and Energy Harvesting Materials
- Iron-based superconductors research
- Advanced Memory and Neural Computing
- Quantum Mechanics and Non-Hermitian Physics
- Magnetic properties of thin films
- Superconductivity in MgB2 and Alloys
- Chemical and Physical Properties of Materials
- Neurosurgical Procedures and Complications
- Marine Biology and Environmental Chemistry
NTT Basic Research Laboratories
2024-2025
University of Occupational and Environmental Health Japan
2024
The University of Tokyo
2017-2024
Kokura Memorial Hospital
2022-2024
Kansai Medical University
2019
Kyushu University
2019
Nagano Matsushiro General Hospital
2019
Fukushima Medical University
2019
Iwate Medical University
2019
Osaka University
2019
A well known semiconductor Cd3As2 has reentered the spotlight due to its unique electronic structure and quantum transport phenomena as a topological Dirac semimetal. For elucidating controlling state, high-quality thin films have been highly desired. Here we report development of an elaborate growth technique high-crystallinity high-mobility with controlled thicknesses observation Hall effect dependent on film thickness. With decreasing thickness 10 nm, states exhibit variations such change...
Electronic structure of quantum-confined Dirac semimetal is elucidated by establishing carrier control techniques in films.
Unconventional surface states protected by non-trivial bulk orders are sources of various exotic quantum transport in topological materials. One prominent example is the unique magnetic orbit, so-called Weyl semimetals where two spatially separated Fermi-arcs interconnected across bulk. The recent observation Hall Dirac semimetal Cd3As2 bulks have drawn attention to novel quantization phenomena possibly evolving from orbit. Here we report oscillation and its evolution into thin film samples,...
Here, we study the effects of a GaAs buffer layer on structural, magnetic, and transport properties Cr$_y$(Bi$_x$Sb$_{1-x}$)$_{2-y}$Te$_3$ magnetic topological insulator thin films compare them with those V$_y$(Bi$_x$Sb$_{1-x}$)$_{2-y}$Te$_3$, which recently reported. Similar to case growth leads some distinctly different than direct InP substrates. These include improved interface quality confirmed by transmission electron microscopy, enhanced coercive fields, smaller resistivity peaks at...
Cd3As2 has long been known as a high-mobility semiconductor. The recent finding of topological semimetal state in this compound demanded growth epitaxial films with high crystallinity and controlled thickness. Here we report the structural characterisation grown on SrTiO3 substrates by solid-phase epitaxy at temperatures up to 600 C employing optimised capping layers substrates. As triangular lattice is epitaxially stacked Ti square (001) substrate, producing (112)-oriented exhibiting...
The newly discovered topological Dirac semimetals host the possibilities of various phase transitions through control spin-orbit coupling as well symmetries and dimensionalities. Here, we report a magnetotransport study high-mobility (Cd1-xZnx)3As2 films, where semimetal can be turned into trivial insulator via chemical substitution. By high-field measurements with Hall-bar geometry, magnetoresistance components ascribed to chiral charge pumping have been distinguished from other extrinsic...
We report an above-room-temperature ferromagnetic state realized in a proximitized Dirac semimetal, which is fabricated by growing typical semimetal Cd$_3$As$_2$ films on garnet with strong perpendicular magnetization. Observed anomalous Hall conductivity substantially large angles found to be almost proportional magnetization and opposite sign it. Theoretical calculations based first-principles electronic structure also demonstrate that the Fermi-level dependent reflects Berry curvature...
To identify XK pathologic mutations in 6 patients with suspected McLeod syndrome (MLS) and a possible interaction between the chorea-acanthocytosis (ChAc)- MLS-responsible proteins: chorein protein.Erythrocyte membrane proteins from MLS ChAc, ChAc mutant carriers, normal controls were analyzed by immunoblotting. We performed mutation analysis immunoblotting to molecularly diagnose MLS. Lysates of cultured cells co-immunoprecipitated anti-XK anti-chorein antibodies.All cases diagnosed MLS,...
While anomalous Hall effect (AHE) has been extensively studied in the past, efforts for realizing large response have mainly limited within intrinsic mechanism. Lately, however, a theory of extrinsic mechanism predicted that magnetic scattering by spin cluster can induce AHE even above ordering temperature, particularly semiconductors with low carrier density, strong exchange coupling, and finite chirality. Here, we find out new semiconductor EuAs, where Eu2+ ions moments form distorted...
Abstract Topological semimetals hosting bulk Weyl points and surface Fermi-arc states are expected to realize unconventional orbits, which interconnect two on opposite sample surfaces under magnetic fields. While the presence of orbits has been proposed play a vital role in recent observations quantum Hall effect even three-dimensional topological semimetals, actual spatial distribution quantized transport experimentally elusive. Here, we demonstrate intrinsic coupling between...
A large intrinsic anomalous Hall effect (AHE) originating in the Berry curvature has attracted growing attention for potential applications. The recently proposed magnetic Weyl semimetal ${\mathrm{EuCd}}_{2}{\mathrm{Sb}}_{2}$ provides an excellent platform controlling AHE because it only hosts a Weyl-point-related band structure near Fermi energy. Here, we report fabrication of single-crystalline films and control their by film technique. As also analyzed first-principles calculations...
We report the growth, structural characterization, and transport properties of quantum anomalous Hall insulator Vy(BixSb1−x)2−yTe3 (VBST) grown on a GaAs buffer layer by molecular beam epitaxy GaAs(111)A substrate. X-ray diffraction transmission electron microscopy show that implementation improves crystal interface quality compared to control sample directly an InP Both samples exhibit effect (QAHE), but, with similar thermal stability despite their different properties. Notably, QAHE in...
Rapid progress of quantum transport study in topological Dirac semimetal, including observations Hall effect two-dimensional (2D) Cd3As2 samples, has uncovered even more interesting properties high-quality and three-dimensional (3D) samples. However, such 3D films with low carrier density high electron mobility have been hardly obtained. Here, we report the growth characterization thick adopting molecular beam epitaxy. The highest (μ = 3 × 104 cm2/Vs) among reported film samples achieved at...
We present a study on magnetotransport in films of the topological Dirac semimetal Cd$_{3}$As$_{2}$ doped with Sb grown by molecular beam epitaxy. In our weak antilocalization analysis, we find significant enhancement spin-orbit scattering rate, indicating that doping leads to strong increase pristine band-inversion energy. discuss possible origins this large comparing Sb-doped other compound semiconductors. will be suitable system for further investigations and functionalization semimetals.
Influences of the polymerization condition on properties electrochemically synthesized polypyrrole film were studied with aim preparing high quality films for device application. Polymerization parameters such as content dissolved oxygen in electrolytic solution, temperature, concentrations monomer and supporting electrolyte, others varied, conductivity, surface morphology, adhesion to substrate resulting examined. High double-layered consisting a thin well adherent sublayer highly...
Role of photo-generated space charges on the memory effect, observed in an iodine-doped conductive polymer / poly(N-vinylcarbazole) (PVK)-trinitrofluorenone (TNF) double-layered system, was investigated by means off voltage-current measurements. The results were consistent with previous conclusion obtained xerographic technique. effect found to come from formed at electrode-photoreceptor interface containing iodine. charge formation induced apparent barrier height lowering against carrier...
A photoinduced memory effect in an electrophotographic receptor consisting of iodine-doped conductive polymer electrode and a poly(N-vinylcarbazole) (PVK)/trinitrofluorenone (TNF) photoreceptor was investigated by means xerographic, voltage-current electrochemical measurements. The results showed that activation energy for formation about 0.23 eV associated with the CT-complex PVK iodine. This led us to propose mechanism this system. Accordingly, it indicated lifetime could be controlled...
While the family of layered pnictides $ABX_2$ ($A$ : rare or alkaline earth metals, $B$ transition $X$ Sb/Bi) can host Dirac dispersions based on Sb/Bi square nets, nearly half them has not been synthesized yet for possible combinations $A$ and cations. Here we report fabrication EuCdSb$_{\mathrm{2}}$ with largest $B$-site ionic radius, which is stabilized first time in thin film form by molecular beam deposition. crystallizes an orthorhombic $Pnma$ structure exhibits antiferromagnetic...
We have fabricated a superconductor/semiconductor junction composed of Al and InAs using cleaved edge overgrowth. By exploiting the unique geometry with thin Al/Pt/Al trilayer formed on side surface an in situ quantum well heterostructure wafer, we achieve superconducting critical field ∼5 T, allowing superconductivity Hall (QH) effects to coexist down filling factor ν = 3. Andreev reflection at zero magnetic shows conductance enhancement limited solely by Fermi velocity mismatch,...
A remarkable photo-induced illumination memory was observed in an iodine-doped conductive polymer/poly(N-vinylcarbazole) (PVK)-trinitrofluorenone (TNF) double-layered system. The measured as a lowering of charge acceptance and investigated function various parameters such the wavelength, intensity exposure incident light. It found that interface between polymer containing iodine photoconductor is responsible for this phenomenon effect caused by carriers generated photoconductor. needed to...
We report fabrication of ${\mathrm{EuSb}}_{2}$ single-crystalline films and investigation their quantum transport. First-principles calculations demonstrate that is a magnetic topological nodal-line semimetal protected by nonsymmorphic symmetry. Observed Shubnikov-de Haas oscillations with multiple frequency components exhibit small effective masses two-dimensional field-angle dependence even in 250 nm thick film, further suggesting possible contributions surface states. This finding the...
We investigate edge and bulk states in Weyl-orbit based quantum Hall effect by measuring a Corbino-type device fabricated from topological Dirac semimetal (Cd1-xZnx)3As2 film. Clear plateaus are observed when one-sided terminals of the device. This indicates that form closed trajectories consisting Fermi arcs chiral zero modes independently on inner outer sides. On other hand, resistance does not diverge at fields where plateau appears, suggesting Weyl orbits region completely localized...
We investigate edge and bulk states in Weyl-orbit based quantum Hall effect by measuring a Corbino-type device fabricated from topological Dirac semimetal (Cd1−xZnx)3As2 film. Clear plateaus are observed when one-sided terminals of the device. This indicates that form closed trajectories consisting Fermi arcs chiral zero modes independently on inner outer sides. On other hand, resistance does not diverge at fields where plateau appears, suggesting Weyl orbits region completely localized...